"A Yemeni security official, speaking on the condition of anonymity, told CNN that security forces sent hundreds of additional troops to the volatile Shabwa province to help in the ongoing search for al-Awlaki, now on a CIA and military hit list to be captured or killed."

Security forces and local tribesmen began the hunt for al-Awlaki last week, regarded by the United States as a terrorist and propagandist who has become an important operational figure within al Qaeda in the Arabian Peninsula, or AQAP.